import java.util.Scanner;

public class Test {
    public static void main(String[] args) {
        int count = 0;
        for (int i = 1; i <= 100; i++) {
            if(i % 10 == 9) {//判断个位的9
                count++;
            }
            if(i/10 == 9) {
                count++;//判断十位的9
            }
        }
        System.out.println(count);
    }

    public static void main9(String[] args) {
        int i = 0;
        int count = 0;
        for(i=1;i<+100;i++){
            if(i%10==9){
                count++;
                //break;
            } if(i/10==9){
                count++;
            }

        }System.out.println(count);
    }
    public static void main8(String[] args) {
        int i = 0;
        int j = 0;

        for(i=1;i<101;i++){
            for(j=2;j<i;j++){
                if(i%j==0){
                    //System.out.println(i);
                break;
                }
            }
            if(j>=i){
                System.out.println(i);
        }

        }
    }
    public static void main7(String[] args) {
        Scanner sc = new Scanner(System.in);
        int a = sc.nextInt();
        int i;
        for( i = 2;i < a;i++){
            if(a%i==0){
                System.out.println(a+"不是素数");
                break;
            }
            }
        if(i>=a){
            System.out.println(a+"是素数");
        }

    }
    public static void main6(String[] args) {
        System.out.println(10>20&&10/0==0);//false
        System.out.println(10<20||10/0==0);//true
    }
    public static void main5(String[] args) {
        int a = 10;
        int b = 20;
        System.out.println(a == b);//false
        System.out.println(a !=b);//true
        System.out.println(a>b);//true
        System.out.println(a<b);//false
        System.out.println(a<=b);//true
        System.out.println(a>=b);//false
    }
    public static void main4(String[] args) {
        int a = 1;
        a+=2;
        System.out.println(a);//输出3
        a-=2;
        System.out.println(a);//输出1
        a*=2;
        System.out.println(a);//输出2
        a%=2;
        System.out.println(a);//输出0
    }
    public static void main3(String[] args) {
        double a = 6.5;
       int b = 2;
        System.out.println(a/b);
        System.out.println(a%b);
    }
    public static void main2(String[] args) {
        int a = 10;
        int b = 20;
        System.out.println(a+b);
        System.out.println(a-b);
        System.out.println(a*b);
        System.out.println(a/b);
        System.out.println(a%b);
        int c = 3;
        int d = 2;
        System.out.println(c/d);
        //在数学中的结果为1.5，但是在Java中会向下取整，即小数点后面的全部舍去，结果为1
        //如果要得到1.5，就要把类型改为double类型
        double e = c/d;
        System.out.println(e);
        //此时输出结果就是1.5
    }
    public static void main1(String[] args) {
        int a = 10;
        int b = 20;
        int c = a+b;
        System.out.println(a+b);
    }
}
